Enum values

APPEND

If there is existing pending (uncompleted) work with the same unique name, append the
newly-specified work as a child of all the leaves of that work sequence. Otherwise, insert
the newly-specified work as the start of a new sequence.
Note: When using APPEND with failed or cancelled prerequisites, newly enqueued work
will also be marked as failed or cancelled respectively. Use
APPEND_OR_REPLACE to create a new chain of work.

APPEND_OR_REPLACE

If there is existing pending (uncompleted) work with the same unique name, append the
newly-specified work as the child of all the leaves of that work sequence. Otherwise, insert
the newly-specified work as the start of a new sequence.
Note: If there are failed or cancelled prerequisites, these prerequisites are
dropped and the newly-specified work is the start of a new sequence.